It simplifies it and allows wide kick to be performed, even when IRQs are disabled, without an asynchronous level in the middle.
This comes at a cost of some more overhead on features like perf and posix cpu timers slow-paths, which is probably not much important for nohz full users. Requested-by: Peter Zijlstra <[email protected]> Reviewed-by: Chris Metcalf <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Luiz Capitulino <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Viresh Kumar <[email protected]> Signed-off-by: Frederic Weisbecker <[email protected]> --- kernel/time/tick-sched.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 9d7a053..f6a980f 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -232,24 +232,20 @@ void tick_nohz_full_kick_cpu(int cpu) irq_work_queue_on(&per_cpu(nohz_full_kick_work, cpu), cpu); } -static void nohz_full_kick_ipi(void *info) -{ - /* Empty, the tick restart happens on tick_nohz_irq_exit() */ -} - /* * Kick all full dynticks CPUs in order to force these to re-evaluate * their dependency on the tick and restart it if necessary. */ void tick_nohz_full_kick_all(void) { + int cpu; + if (!tick_nohz_full_running) return; preempt_disable(); - smp_call_function_many(tick_nohz_full_mask, - nohz_full_kick_ipi, NULL, false); - tick_nohz_full_kick(); + for_each_cpu_and(cpu, tick_nohz_full_mask, cpu_online_mask) + tick_nohz_full_kick_cpu(cpu); preempt_enable(); } -- 2.7.0
